Native flora and introduced plants of the ecologically important Pilliga Forests of Northwestern NSW

Saturday, July 14, 2012

Pterostylis curta

Pterostylis curta - Blunt Greenhood

Family: Orchidaceae

Common name: Blunt Greenhood

Flowers: A single large erect flower 3.5cm long, green and white with brown shading towards the apex. The labellum (tongue) is long and twisted to one side. This twist is an identifying feature of Pterostylis curta. Flowering period from Aug to Oct. [Note: anomalies can occur in the plant world, and a Pterostylis curta plant that I photographed in the Pilliga had two flowers rather than the specified single flower.]

Leaves and stem: A central stem to 30cm tall emerges from a basal rosette of 3 to 6 fleshy green, stalked leaves, up to 10cm by 3cm, often with wavy margin.

Habit: This terrestrial orchid often grows in extensive colonies and flowers freely. I was told about a colony of greenhood orchids in a particular place in the Pilliga and went to investigate, finding most had already perished with only a few remaining flowering. A colony of flowering Pterostylis curta can be quite spectacular.

Habitat: I found the Blunt Greenhoods growing in a damp grassy shady area in the Pilliga. All the images I have here indicate the lush growth of grasses and herbs, and the usual habitat of Pterostylis curta is recorded as moist sheltered areas in open forest, woodland and heathy forest. It also occurs in Qld, Vic, Tas, SA, and ACT.

[Note:Pterostlis curta is not included in Leo Butler's April 2009 list of plants in the Pilliga Forests.]

The Pilliga Forest is the largest remaining continuous remnant of semi-arid woodland in NSW, consisting of about 500,000 hectares of public bushland. The environment changes from cypress pine to ironbark to scribbly gum to box, and back again, interspersed with expansive heaths and a network of sandy creeks. The Pilliga is recognised as one of the most important areas for biodiversity in eastern Australia and is home to more than 350 species of birds, mammals, reptiles and frogs. To many who travel through the area, the woodlands might look monotonous, but if you drive the back roads slowly or wander amongst the vegetation, you will discover that The Pilliga is full of life and richness and wonder. It is truly a special place, and of huge significance to the survival of countless native plants and animals.